Science Musings Blog

Tuesday, June 03, 2014

Google Earth

Although the main action is now going to be on Saturday, I’ll be occasionally posting on other days of the week; perhaps Anne or Tom too. What follows is a few words on Chattanooga, where Mr. Fix-It takes place, setting the scene, so to speak.

East Tennessee is topologically a series of parallel northeast-southwest tending ridges and valleys, a continuation of the Ridge and Valley Province of western Virginia and central Pennsylvania. The Tennessee River, as a well-behaved river should, flows down along one of these valleys, meandering this way and that along the valley floor.

Then, at Chattanooga, my old home town, the river does a most surprising thing. Instead of continuing down the valley and making its unimpeded way to the Gulf, the river makes a sharp right turn and carves its meandering way through the Cumberland Plateau, eventually swinging north and spilling into the Ohio River.

This is the sort of improbable puzzle that geographers and geologist thrive on. In this case, of course, the answer to the riddle has been around for a long time: the river was there before the ridge; as the plateau went up, the river stubbornly kept to its course, chewing down into the sandstone rocks.

That river gap in the ridge gave the place a strategic importance, and was fiercely fought over during the Civil War. The pointy mountain just below the southwest corner of the X box is Lookout Mountain, scene of "The Battle Above the Clouds." The narrow dark band that passes between the t and a of "Chattanooga" is Missionary Ridge, successfully stormed by the bluecoats. And the dark rectangle almost halfway between the t and a and the bottom of the image is the blood-soaked ground of Chickamauga.

All of this was an integral part of my growing up, and still haunts my dreams. There is a story for every square mile of the image above – a hike, a swim, a spelunk, a fright, a misdemeanor, a kiss. Continents collide. Mountains rise. Rivers bite and roll. Hundreds of millions of years to shape a geography. Twenty years for a geography to shape a man.